Portable space heater and surface heating system

ABSTRACT

A portable space heater includes a housing with an air inlet through which ambient air is received and an air vent through which heated air is expelled. A centrifugal fan of the heater is configured to drive air flow into the air inlet. A flow channel of the heater is configured to direct the air flow toward the air vent and a heating element heats the air flow in the flow channel. The heater additionally includes a sensor configured to sense proximity of a body part to the air vent and a controller configured to pause operation of the heating element based on the sensing, wherein the centrifugal fan, the flow channel, the heating element, the sensor and the controller are housed in the housing.

RELATED APPLICATION/S

This application claims the benefit of priority of U.S. Provisional Patent Application No. 62/870,075 filed on Jul. 3, 2019, the contents of which are incorporated herein by reference in their entirety.

FIELD AND BACKGROUND OF THE INVENTION

The present invention, in some embodiments thereof, relates to portable space heaters and surface heating systems and, more particularly, but not exclusively, to space heaters and surface heating systems adapted for infants and young children.

Portable space heaters may pose a safety hazard especially for infants and young children. A child or even an adult may for example touch the heater and get burned. The heater may also topple over. If the heater topples over on a flammable surface, the surface may catch on fire. Furthermore, for space heater operating with a fan that blows heated air into the room, there is a danger of injury if a person inserts a finger or an object through a grill of the fan.

Vornado Air Circulation Systems, Inc. in Andover, Kans. is known to market a space heater that is designed to be baby safe. The heater is described in website www(dot)vornadobaby(dot)com/product/sensa/. This portable space heater includes an axial fan that blows warm air. The axial fan is protected with a grid designed to resist penetration of a finger. The heater is also designed to stay cool to the touch and automatically shut off if excessive heat is detected or if the heater is tipped over. One of the drawbacks of this space heater is that although a child may not be able to insert a finger through the grid, it may still be possible for a child to insert an object such as a stick through the grid and block rotation of the fan.

Surface heaters are also known and available in the market. Surface heaters are commonly used for heating a bed surface. The most common type is an electric blanket. Electric blankets include a heating element inserted into a fabric that heats when plugged into an outlet. It is typically recommended not to sleep with an electric blanket for safety reasons. Other known systems operate based on blowing air onto the bed surface or based on circulating a liquid through channels formed within a mattress cover.

US Patent Application Publication No. 20150121620 entitled “Bedding climate control apparatus with forced airflow for heating and ventilating,” describes a bedding climate control apparatus that delivers, forced airflow from a fan/blower within a housing to selectively deliver tempered (heated via a thermal element) and untempered (room temperature) air through a flexible hose to bedding. Temperature may be set remotely via a wireless remote control and via a Bluetooth enabled device.

US Patent Application Publication No. 20160029808 entitled “Article comprising a temperature-conditioned surface, thermoelectric control unit, and method for temperature-conditioning the surface of an article,” describes a thermoelectric control unit adapted for regulating liquid temperature in a hydraulic circuit. The control unit includes a housing, and a liquid reservoir for containing a liquid inside the housing. The reservoir has a fill opening, a liquid outlet, and a liquid return. A conduit assembly extends from the liquid outlet to the liquid return. A pump is operatively connected to the reservoir, and is adapted for moving the liquid through the conduit assembly within the hydraulic circuit. A first heat exchanger communicates with the liquid reservoir. A second heat exchanger resides adjacent the first heat exchanger, and communicates with an environment outside of the liquid reservoir and inside of the housing. A substantially planar thermoelectric cooling module is located at an electrified junction between the first and second heat exchangers.

SUMMARY OF THE INVENTION

According to some example embodiments, there is provided a portable space heater configured to suitable for use with infants and small children. In some example embodiments, the portable space heater includes one or more sensors to sense a potentially dangerous situation and a controller configured to pause generating heated air based on the sensing. Optionally, the sensors may sense approach of a body part near an air vent of the heater, jolting or toppling of the heater, and/or overheating of the heater.

According to some example embodiments, the portable space heater is configured to be interchangeably operated as a standalone portable space heater and as a part of a surface heating system configured to heat a dedicated mat such as a playmat. In some example embodiments, the interchangeably operation is based on connecting one of a grill holder and a mat connector to an air vent of the portable space heater.

In some example embodiment, the dedicated mat includes air flow channels through which warm air from the portable space heater may flow to warm the dedicated mat. Optionally, connection between the portable space heater and dedicated mat is configured to heat the dedicated mat with no electrical contact between the mat and the heater. In some example embodiments, the connector is an elongated tube displacing the heater from the mat and thereby avoiding accidental contact of an infant or small child with the heater while on the mat. According to some example embodiments, there is provided a kit including the portable space heater, the mat and the mat connector.

According to an aspect of some example embodiments, there is provided a portable space heater comprising: a housing including an air inlet through which ambient air is received and an air vent through which heated air is expelled; a centrifugal fan configured to drive air flow into the air inlet; a flow channel configured to direct the air flow toward the air vent; a heating element configured to heat the air flow in the flow channel; a sensor configured to sense proximity of a body part to the air vent; and a controller configured to pause operation of the heating element based on the sensing, wherein the centrifugal fan, the flow channel, the heating element, the sensor and the controller are housed in the housing.

Optionally, the sensor includes an inductive coil and is configured to sense a change in magnetic field based on proximity of a body part.

Optionally, the coil encompasses the air vent.

Optionally, the portable space heater includes an accelerometer configured to sense jolting of the portable space heater, wherein the controller is configured to pause operation of the heating element based on sensing the jolting.

Optionally, the portable space heater includes a temperature sensor, wherein the temperature sensor is configured to sense temperature inside the housing and wherein the controller is configured to pause operation of the heating element based on sensing a temperature above a pre-defined temperature.

Optionally, the portable space heater includes a cylindrically shaped thermal insulator and a metal guard, wherein the heating element is housed in the cylindrically shaped thermal insulator and the metal guard is positioned on one end of the cylindrically shaped thermal insulator.

Optionally, the portable space heater includes a control panel configured for user interface; a ring shaped optical diffuser encompassing the control panel; and an LED positioned under the ring shaped optical diffuser, wherein the LED is configured to illuminate through the ring shaped optical diffuser.

Optionally, the control panel includes a touch screen and wherein the controller is configured to automatically lock the touch screen based on sensing an idle period.

Optionally, the portable space heater includes a grill assembly including a grill holder and a grill, wherein the grill includes a plurality of blades extending into the air vent and fixedly angled with respect to direction of the air flow through the flow channel.

Optionally, the grill holder is configured to connect to an adaptor.

Optionally, the portable space heater includes an air vent adaptor configured to removably receive the grill holder.

According to an aspect of some example embodiments, there is provided a mat comprising: a first layer formed with at least one open air channel extending from an edge of the first layer in a direction along a surface of the first layer; a second layer overlaid on a surface of the first layer exposing the at least one open air channel, wherein the second layer includes an array of air holes, and wherein the array of air holes overlap with the at least one open air channel; and an inlet port mounted on the edge of the first layer and configured to direct air flow from an external source through the at least one open air channel.

Optionally, the mat includes a third layer overlaid on the second layer, wherein the third layer is a layer of fabric.

Optionally, the fabric is 3D mesh fabric.

Optionally, the at least one open air channel includes a plurality of open air channels and wherein the plurality of open air channels extend across the mat and are spaced from one another.

Optionally, the spacing between each of the plurality of open air channels varies with distance from the inlet port.

Optionally, the plurality of open air channels is formed with a gradient diameter, wherein the diameter increases with distance from the inlet port.

Optionally, the at least one open air channel is 1 mm-50 mm deep and a diameter of the open air channel is 5 mm-50 mm.

Optionally, the first layer is formed with polyethylene or ethylene vinyl acetate and wherein the at least one open air channel is integral to the first layer and is formed by molding.

Optionally, the array of air holes is aligned with the at least one open air channel.

Optionally, the array of air holes is asymmetrically spread over the second layer.

Optionally, a diameter of the air holes 1.5 mm-3.5 mm.

Optionally, a thickness of the second layer is 0.5 cm-2.5 cm.

Optionally, the at least one air channel and the array of air holes are spatially positioned and patterned to provide a uniform temperature across the mat based on air flowing through the at least one air channel and the array of air holes.

Optionally, the second layer is formed from polyethylene closed cell foam.

According to an aspect of some example embodiments, there is provided a tube assembly configured to direct air from an air vent to a mat including at least one air channel therein, the tube assembly comprising: a pair of tubes; a Y shaped tube connector connected at one end of the pair of tubes: a pair of tube connectors connected at a second end of the pair of tubes; and

a sleeve covering the pair of tubes.

Optionally, the sleeve is formed with thermally insulating material.

Optionally, the pair of tube connectors is configured to be removably connected to an outlet port with a child safe connection and wherein the Y shaped tube connector is configured to be removably connected to an inlet port with a child safe connection.

According to an aspect of some example embodiments, there is provided a surface heating system comprising: the portable space heater as described herein; the mat as described herein; and the tube assembly as described herein, wherein the tube assembly is configured to connect the air vent of the portable space heater to the inlet port on the mat.

Optionally, the surface heating system includes a pair of mats, wherein the connector is configured to connect each of the pair of mats to the air vent of the portable space heater.

According to an aspect of some example embodiments, there is provided a kit comprising: the portable space heater as described herein; a grill assembly including a grill holder, wherein the grill holder is configured to connect to an adaptor; an air vent adaptor configured to removably receive the grill holder; the mat as described herein; and the mat connector as described herein.

Optionally, the grill includes a plurality of blades extending into the air vent and fixedly angled with respect to direction of the air flow through the flow channel.

Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings. With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced.

In the drawings:

FIG. 1 is a perspective view of an example portable space heater in accordance with some example embodiments;

FIGS. 2A, 2B and 2C are top, front and side views of the example portable space heater, all in accordance with some example embodiments;

FIGS. 3A and 3B are exploded views of an example grill assembly fitted in the vent opening of the portable space heater and a perspective view of the grill, both in accordance with some example embodiments;

FIG. 4 is a bottom view of the portable space heater in accordance with some example embodiments;

FIG. 5 is a perspective view of an example portable space heater connected to a playmat, in accordance with some example embodiments;

FIG. 6 is a perspective view of an example tube assembly in accordance with some example embodiments;

FIGS. 7A and 7B are a perspective view and an exploded view of an example playmat, both in accordance with some example embodiments;

FIGS. 8A and 8B are a top view and a side view of an example layer in the playmat including air channels, both in accordance with some example embodiments;

FIG. 9 is a top view of an example layer in the playmat including an array of through going air holes in accordance with some example embodiments;

FIG. 10 is a cross-sectional view of an example space heater in accordance with some example embodiments;

FIGS. 11A and 11B are example safety features of the space heater in accordance with some example embodiments; and

FIG. 12 is an exploded view of a user interface panel mounted on a housing of the space heater in accordance with some example embodiments.

DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention, in some embodiments thereof, relates to portable space heaters and surface heating systems and, more particularly, but not exclusively, to space heaters and surface heating systems adapted for use with infants and young children.

Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways.

According to some example embodiments, the portable space heater includes a number of safety features configured to prevent injury to a person or accidental fires as a result of an infant or young child tampering with the heater. One example safety features includes using a centrifugal fan as opposed to an axial fan to blow the heated air. The centrifugal fan sucks in air from the surrounding and directs the air via a dedicated flow channel along a heating element and out through an air vent (or air outlet).

An advantage of the centrifugal fan is that its rotating parts are generally enclosed within a housing that the housing with rotating parts may be positioned remote from the air vent and therefore are not easily accessible as a results of tampering.

According to some example embodiments, the portable space heater includes a proximity sensor configured to sense a body part in proximity to the air vent. A controller of the portable space heater may be configured to pause or shut off operation of the heating element of the heater based on detecting proximity of the body part. Optionally, a fan of the heater may continue to operate without operation of the heating element. Optionally, the proximity sensor is an inductive sensor formed with a coil mounted around the air vent. A change in sensed magnetic field may provide input to the controller that a body part or other object may be close to the air vent.

In some example embodiments, the portable space heater includes a temperature sensor configured to monitor internal temperature within the heater, e.g. near the heating element. Optionally, the controller is configured to receive input from the temperature sensor and pause or shut off operation of the heating element based on detecting a temperature above a pre-defined temperature, e.g. 75° C. The temperature sensor may prevent overheating of the heating element in situations in which air flow through the air vent may be blocked.

In some example embodiments, the portable space heater includes an accelerometer configured to detect jolting or toppling of the portable space heater and the controller may be configured to pause or shut off operation of the heating element based on detecting jolting or toppling of the portable space heater. Optionally, the portable space heater may be operated in different orientations, including a horizontal orientation as when positioned on a floor or in a vertical orientation as when hung on a wall.

According to some example embodiments, the air vent is covered with a grill that is sized to prevent penetration of fingers. According to some example embodiments, the grill includes an array of blades or vanes that that extend inwardly at an angle, e.g. an angle of about 30°-60°, e.g. 45° toward a base of the heater. If a child or other person attempts to insert in object through the grill, the blades will direct the object at the angle and away from the heating element and the centrifugal fan housed in the heater.

According to some example embodiments, a grill assembly including the grill and a grill holder may be removed from the air vent. The grill holder includes a clasping element (a connector) that is child safe, e.g. a child would not be able to remove the grill holder. Optionally, the grill assembly is configured to be removed from the air vent by an adult and replaced with another connector, e.g. a mat connector configured for use with the surface heating system.

According to some example embodiments, additional safety features include a metal guard near the heating element and within the heater that is configured to prevent access to the heating element and a protective cover configured to insulate the heating element so that an outer cover of the heater stays cool to the touch.

Optionally, the heater includes a plurality of operational buttons on a control panel that may be controlled via a touch screen. In some example embodiments, the touch screen includes a child safe locking feature that is configured to automatically lock the control panel during idle periods of the touch screen. Unlocking is configured to be child safe. Optionally, lighting is configured to illuminate through a portion of a translucent cover that covers the control panel. Optionally, the lighting may be used as a night light.

According to some example embodiments, the surface heating system includes a dedicated mat with one or more air channels that extend through the mat generally parallel to a surface of the mat. In some example embodiments, the mat additional includes a plurality of through going air holes penetrating out through the surface of the mat. During operation of the system, warm air flow received from the heater flows through the air channel(s) and is expelled via the air holes. The flow of warm air is configured to warm the mat as well as warm an area above the mat. The heating is based on conduction as well as convection. The warm air flowing through the air channels may warm the surface of the mat via conduction and the warm air expelled through the air holes and fabric may provide warming via convection.

In some example embodiments, the mat is formed from a plurality of layers. Optionally, a first layer includes open air channels through which the air from the heater flows in a direction that is generally parallel to a surface of the mat. A second layer overlaying the first layer may include the array of air holes through which air flowing in the air channels is expelled. An optional additional layer may be a fabric material that is overlaid on the second layer. Optionally, the fabric material is configured to scatter the air expelled through the array of air holes. Optionally, the fabric material is three dimensional mesh fabric.

According to some example embodiments, the number of air channels, size of the air channels, spatial positioning of the air channels, as well as number of air holes, size of the air holes and spatial position of the air holes may be selected to provide uniform heating along the mat, e.g. relatively low temperature gradients across the mat.

According to some example embodiments, the mat is a playmat and is configured to be child safe. Optionally, the mat is connected to the space heater through an elongated tube through which warm air is delivered. The playmat may be electrically insulated from the portable space heater with non-electrically conducting materials connecting the portable space heater with the playmat, e.g. the elongated tube may be formed from insulating or non-electrically conducting material. Additionally, no electricity, electrical components or electrical wiring runs through the elongated tube between the playmat and the heater. In this manner, a child or infant using the playmat may not be in danger of being electrocuted due to malfunction of the portable space heater. The elongated tube also provides for physically displacing the heater from the playmat and the infant or child on the playmat. Optionally, the playmat is foldable and portable.

Reference is now made to FIG. 1 a perspective view of an example portable space heater and to FIGS. 2A, 2B and 2C showing top, front and side views of the example portable space heater, all in accordance with some example embodiments. Portable space heater 100 includes a cover 110 (or housing), one or more legs 140 on which heater 100 may be supported, a control panel 130 providing a user interface for controlling operation of heater 100, a power cord 150 and an air vent 113 that is covered with a grill assembly 120 and through which warm air is expelled. Optionally, a portion of cord 150 may be wrapped around legs 140 to adjust extended length of cord 150.

Heater 100 additionally includes an air inlet 112 through which ambient air may be sucked into heater 100 (FIG. 2A). Optionally, air inlet 112 includes a grill and an air filter 108 (FIG. 10) through which air penetrates into heater 100. Air filter 108 may be configured to remove dust and allergens from the air flowing into heater 100. Optionally, air inlet 112 is on an opposite facing side of heater 100 with respect to the air vent 113. In some example embodiments, one or more handles 115 may be integrated on cover 110.

Reference is now made to FIGS. 3A and 3B showing exploded views of an example grill assembly fitted in the vent opening of the portable space heater and a perspective view of the grill, both in accordance with some example embodiments. According with some example embodiments, grill assembly 120 may be configured to be removable. Grill assembly 120 may include for example a grill holder 116 and a grill 125. Grill holder 116 fixedly supports grill 125 and also includes a female or male part of a connector that can be securely snapped into an air vent adaptor 127. Optionally, grill holder 116 and grill 125 are one integrated part. Air vent adaptor 127 is fixedly attached to cover 110. Optionally, connection between grill holder and air vent adaptor 127 is configured to be child proof so that only an adult may succeed in attaching and detaching grill assembly 120 from cover 110.

Reference is now made to FIG. 4 showing a bottom view of the portable space heater in accordance with some example embodiments. Portable space heater 100 may be operated while in a horizontal position as when positioned on a floor and may also be operated in a vertical position while hanging on a wall or other vertical surface. Optionally, a bottom surface 112 of portable space heater 100 includes an opening 145 in which a nail or screw may be placed for hanging.

Reference is now made to FIG. 5 showing a perspective view of an example portable space heater connected to a playmat in accordance with some example embodiments. According to some example embodiments, heater 100 may be connected and operated with a playmat 301 that is configured to be heated with heated air flowing from heater 100 to playmat 301 via tube assembly 160. Surface heating system 300 includes heater 100 together with tube assembly 160 and playmat 301. In the example shown, playmat 301 is the surface that is heated by system 300. In other example embodiments, playmat 301 may be replaced by a bed mat or an exercise mat.

In some example embodiments, a connector 162 at a first end of tube assembly 160 is fitted into receiving frame 127 of air vent 113 in place of grill assembly 120 (FIG. 1). Optionally, connector 162 is a Y shaped tube connector. Optionally, one or more connectors 167 at a second opposite end are connected to playmat 301. Tube assembly 160 may include one or more tubes that are either rigid or flexible. Optionally, tube assembly 160 provides for displacing heater 100 from a vicinity of playmat 301 on which a baby or child is positioned for safety reasons. Optionally, playmat 301 includes two playing surfaces that are connected along fold line 302 so that playmat 301 may be folded while stored. Optionally, playmat 301 is additionally installed with a pair of handles 305 for carrying playmat 301. Size of playmat 301 may span 0.25 m²-9 m² and may optionally be folded over a plurality of fold lines, e.g. two or more fold lines. Although a rectangular playmat is shown as an example, other shapes are also contemplated, e.g. circular, star shaped or irregular shapes. Playmat may be formed with a plurality of discrete sections that are held together with a fabric cover.

Reference is now made to FIG. 6 showing a perspective view of an example tube assembly in accordance with some example embodiments. Optionally, tube assembly 160 includes a single connector 162 that is configured to be snap fitted into air vent adaptor 127 to provide air flow through one or more tubes 161, e.g. two tubes 161. Alternatively, other types of connectors may be contemplated, e.g. a screw thread connector. Optionally, single connector 162 may be angled so that tubes 161 may connect to adaptor 127 while tubes 161 may lay flat against the floor or other surface on which playmat 301 is placed.

Optionally, tubes 161 run parallel to each other and are covered with a covering layer 163. The covering layer 163 may be a thermal insulator that does not tend to get heated while warm or hot air flows through tubes 161. Covering layer 163 may hold tubes 161 together to prevent a person or child from getting tangled between tubes 161. An opposite end of tube assembly 160 may include one or more connectors 167, e.g. two connectors as shown each of which is configured to connect to a port in playmat 301. Connectors 167 may be for example snap connectors or screw thread connectors and may be child proof.

Reference is now made to FIGS. 7A and 7B showing a perspective view and an exploded view of an example playmat, both in accordance with some example embodiments. According to some example embodiments, a playmat 301 may be formed from a plurality of layers. Optionally, an upper layer may be formed from a fabric material 320, e.g. a three dimensional (3D) mesh fabric. Fabric material 320 may include openings 366 for receiving ports 367 that are configured to connect with tube assembly 160. Optionally handles 305 may also be installed or sewn on fabric material 320. According to some example embodiments, fabric 320 fits over and encloses each of middle layer 330 and bottom layer 340. Middle layer 330 and bottom layer 340 may be fixedly attached to each other, e.g. glued. Optionally, fabric material 320 is sized to cover a pair of middle layers 330 fixedly attached to a pair of bottom layers 340 and thereby define a larger area mat from a plurality of sections.

According to some example embodiments, bottom layer 340 includes at least one and preferably a plurality of channels that run along a surface of bottom layer 340 and collect at an air inlet area 368 that aligns with ports 367. Bottom layer 340 may be formed with a plastic material and may optionally be rigid. According to some example embodiment middle layer 330 includes an array of air holes that penetrate through a thickness of the layer. Optionally, air holes are generally perpendicular to middle layer 330 but may also be at an angle with respect to middle layer 330. Optionally, thickness of the playmat is 0.5 cm-2.5 cm.

Reference is now made to FIGS. 8A and 8B showing a top view and a side view of an example layer in the playmat including air channels, both in accordance with some example embodiments. According to some example embodiments, bottom layer 340 is a plastic layer formed for example with polyethylene (PE) foam, e.g. closed cell foam or ethylene vinyl acetate (EVA). Optionally, bottom layer may include two solid plates 341 that are connected with a hinge and together span the area of bottom layer 340. According to some example embodiments, open air flow channels 345 are formed on bottom layer 340. The channels may for example be integral to the layer based on molding. A depth of channels 340 may be 1 mm-15 mm or up to 50 mm depending on thickness of bottom layer 340. Optionally, layer thickness of bottom layer 340 may be 3 mm-25 mm, e.g. 18 mm or up to 55 mm.

Open air flow channels 345 are configured to direct warm air delivered by heater 100 from inlet area 368 across the surface of bottom layer 340. In some example embodiments, air flow channels 345 are formed with a gradient diameter. Diameter of air channels 345 may be 5 mm-50 mm or 10 mm-20 mm. In some example embodiments, larger diameter channels are formed in areas away from inlet area 343 as compared to air flow channels 345 that are more proximal to inlet area 368. Optionally, the gradient diameter is configured to provide a near constant temperature across the surface of playmat 301. Optionally, air flow channels run generally parallel to each other along a surface of bottom layer 340 and may be spaced at distances of 5 cm-20 cm or 7 cm-12 cm. Optionally, spacing between the air channels 345 are selectively varied across the bottom layer. Optionally, the generally parallel portion of air channels 345 are more sparsely spaced from one another near inlet area 368 and more densely spaced from one another distal from inlet 368.

Reference is now made to FIG. 9 showing a top view of an example layer in the playmat including an array of through going air holes in accordance with some example embodiments. According to some example embodiments, middle layer 330 includes an array of air holes 335, e.g. pin holes that are aligned with air channels 345 in bottom layer 340. In some example embodiments, middle layer 330 is formed from PE closed cell foam. Optionally, diameter of air holes 335 may be 1.5 mm-3.5 mm.

In some example embodiments, air holes 335 are sparsely spaced in an area near air inlet area 368 or may be absent in an area near air inlet area 368 and more densely spaced at a distance from air inlet area. Optionally, an array of air holes 335 may be distributed asymmetrical over a first portion of middle layer 330 and may be distributed symmetrically over a second portion of middle layer 330. Optionally, less or no air holes are positioned near an inlet of air into playmat 301. Optionally, at least a portion of air holes 335 are arranged in a square grid with holes that are 5-20 cm apart. Thickness of the layer may be 5-15 mm, e.g. 9 mm. Optionally, middle layer 330 is thinner than bottom layer 340, e.g. half the thickness of lower layer

Reference is now made to FIG. 10 showing a cross-sectional view of an example space heater and to FIGS. 11A and 11B showing example safety features of the space heater, all in accordance with some example embodiments. According to some example embodiments, heater 100 includes a centrifugal fan 101 that is configured to blow air through a channel 105 including a heating element 102 and out through a grill assembly 120 including grill 125. Grill 125 includes blades that are angled at about 30°-60°, e.g. 45° toward a base of heater 100 and/or in relation to a longitudinal axis 124 of heating element 102 through which air flow in the heater is directed. Optionally, heater 100 may be configured to be placed on a floor and grill 125 may direct air flow upwards and/or heater 100 may be hung on a wall and grill 125 may direct heat away from the wall. Optionally, grill assembly 120 may be removed and replaced with tube assembly 160 (FIG. 6) that is configured to connect heater 100 to playmat 301 or other dedicated surface.

According to some example embodiments, an induction sensor including a coil 174 positioned in housing 110 around grill assembly 120 is configured to detect a body part or conductive object approaching grill assembly 120 based on a change in a sensed magnetic field. In some example embodiments, the controller switches off or pauses operation of heating element 102 based on detecting a body part or conductive object approaching grill assembly 120. Optionally, fan 101 may continue to operate.

In some example embodiments, heater 100 includes a temperature sensor 172 configured to monitor temperature near heating element 102. Optionally, the controller is configured to switches off or pause operation of heating element 102 based on detecting a temperature above a pre-defined temperature. Optionally, the pre-defined temperature is 70° C. or 75° C. In some example embodiments, temperature sensor 172 may provide for sensing over heating due to a block in the passage way of the air flow as may occur as an example when tubing 160 is pressed upon or folded over, or for example when an object blocks outlet through grill assembly 120. Optionally, heater 100 additionally includes a thermostat for maintaining operating temperature to be up to 60° C. or up to 65° C.

Air may be sucked into heater 100 with centrifugal fan 101 via air inlet 112. The incoming air may be filtered with filter 108. A power supply adaptor 107 may adapt power from an AC source (from a wall outlet) for operating heater 100. In some example embodiments, heating element 102 is covered with a thermal insulator 104. Insulator 104 may be cylindrically shaped and may be configured to prevent cover 110 from getting too hot. Another safety feature includes metal guard 103 that encloses heating element in channel 105 and blocks access to heating element 102.

A user may control operation of heater 100 with control panel 130. Optionally, control panel 130 is touch-sensitive screen. A printed circuit board (PCB) 109 may include circuitry, e.g. a controller for controlling operation of heater 100. In some example embodiments, the controller is configured to lock the touch-sensitive screen with a child safe lock during activation of the heat. Optionally, the controller locks the touch-sensitive screen after 3-20 seconds of operating the heater.

Optionally, PCB includes one or more sensors configured for safety. Optionally, an accelerometer or a gyroscope is included and is configured to sense when the heater is being handled, e.g. toppled over or jolted. Optionally, controller 114 may be configured to turn off or pause operation of heater 100 based on detecting that the heater is being handled. Optionally, PCB 109 includes a wireless communication protocol, e.g. Bluetooth and can be operated remotely. Optionally, PCB includes one or more light emitting diodes (LEDs) 111 that may emit light through control panel 130 and may be used as a night light.

Reference is now made to FIG. 12 showing an exploded view of a user interface panel mounted on a housing of the space heater in accordance with some example embodiments. According to some example embodiments, control panel 100 includes a PCB 109. Optionally, a touch sensitive screen 132 is overlaid on PCB 109. Optionally, a ring shaped optical diffuser 133 surrounds touch screen 132 and secures touch screen 132 in place. Optical diffuser 133 may diffuse light from one or more LEDs mounted on PCB 109.

It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.

All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention.

To the extent that section headings are used, they should not be construed as necessarily limiting. In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety. 

1. A portable space heater comprising: a housing including an air inlet through which ambient air is received and an air vent through which heated air is expelled; a centrifugal fan configured to drive air flow into the air inlet; a flow channel configured to direct the air flow toward the air vent; a heating element configured to heat the air flow in the flow channel; a sensor configured to sense proximity of a body part to the air vent; and a controller configured to pause operation of the heating element based on the sensing, wherein the centrifugal fan, the flow channel, the heating element, the sensor and the controller are housed in the housing.
 2. The portable space heater according to claim 1, wherein the sensor includes an inductive coil and is configured to sense a change in magnetic field based on proximity of a body part.
 3. The portable space heater according to claim 2, wherein the coil encompasses the air vent.
 4. The portable space heater according to claim 1, comprising an accelerometer configured to sense jolting of the portable space heater, wherein the controller is configured to pause operation of the heating element based on sensing the jolting.
 5. The portable space heater according to claim 1, comprising a temperature sensor, wherein the temperature sensor is configured to sense temperature inside the housing and wherein the controller is configured to pause operation of the heating element based on sensing a temperature above a pre-defined temperature.
 6. The portable space heater according to claim 1, comprising a cylindrically shaped thermal insulator and a metal guard, wherein the heating element is housed in the cylindrically shaped thermal insulator and the metal guard is positioned on one end of the cylindrically shaped thermal insulator.
 7. The portable space heater according to claim 1, comprising: a control panel configured for user interface; a ring shaped optical diffuser encompassing the control panel; and an LED positioned under the ring shaped optical diffuser, wherein the LED is configured to illuminate through the ring shaped optical diffuser.
 8. The portable space heater according to claim 7, wherein the control panel includes a touch screen and wherein the controller is configured to automatically lock the touch screen based on sensing an idle period.
 9. The portable space heater according to claim 1, comprising a grill assembly including a grill holder and a grill, wherein the grill includes a plurality of blades extending into the air vent and fixedly angled with respect to direction of the air flow through the flow channel.
 10. The portable space heater according to claim 9, wherein the grill holder is configured to connect to an adaptor.
 11. The portable space heater according to claim 9, comprising an air vent adaptor configured to removably receive the grill holder.
 12. A mat comprising: a first layer formed with at least one open air channel extending from an edge of the first layer in a direction along a surface of the first layer; a second layer overlaid on a surface of the first layer exposing the at least one open air channel, wherein the second layer includes an array of air holes, and wherein the array of air holes overlap with the at least one open air channel; and an inlet port mounted on the edge of the first layer and configured to direct air flow from an external source through the at least one open air channel.
 13. The mat of claim 12, comprising a third layer overlaid on the second layer, wherein the third layer is a layer of fabric.
 14. The mat of claim 13, wherein the fabric is 3D mesh fabric.
 15. The mat of claim 12, wherein the at least one open air channel includes a plurality of open air channels and wherein the plurality of open air channels extend across the mat and are spaced from one another.
 16. The mat of claim 15, wherein the spacing between each of the plurality of open air channels varies with distance from the inlet port, or wherein the plurality of open air channels are formed with a gradient diameter, wherein the diameter increases with distance from the inlet port. 17-18. (canceled)
 19. The mat of claim 12, wherein the first layer is formed with polyethylene or ethylene vinyl acetate and wherein the at least one open air channel is integral to the first layer and is formed by molding, or wherein the array of air holes is aligned with the at least one open air channel, or wherein the array of air holes is asymmetrically spread over the second layer. 20-23. (canceled)
 24. The mat according to claim 128, wherein the at least one air channel and the array of air holes are spatially positioned and patterned to provide a uniform temperature across the mat based on air flowing through the at least one air channel and the array of air holes.
 25. (canceled)
 26. A tube assembly configured to direct air from an air vent to a mat including at least one air channel therein, the tube assembly comprising: a pair of tubes; a Y shaped tube connector connected at one end of the pair of tubes: a pair of tube connectors connected at a second end of the pair of tubes; and a sleeve covering the pair of tubes. 27-32. (canceled) 